Field of the Invention
The present invention relates to a gas turbine, a gas turbine blade and a manufacturing method of gas turbine blade.
Description of Related Art
As a background art of this technical field, there is Japanese Laid-open Patent Application No. 2003-322002 (Patent Literature 1). This patent application states: “The refresh path extends through the inner wall in the radial direction, which inner wall is a boundary of the inner portion of the final flow path in the radial direction, and fluid-interconnects to the cooling air source. The refresh path to the leading edge feed flow path is connected to the flow-in entrance flow path of the serpentine cooling passage passing through the base of the blade and as a result, joins to the flow rate of the serpentine cooling passage. To adjust the flow rate and pressure to the leading edge feed flow path, independently of the flow through the serpentine cooling passage, the cooling flow passing through the refresh path can be adjusted.”
Further, there exists Japanese Laid-open Patent Application No. 2008-151112 (Patent Literature 2). This patent application states: “The plurality of stub portions are mutually gathered in the valve portion connected to the shank portion, are radially extended outward, and are connected integrally with different rod portions among the rod portions so as to increase the strength of the cores.”    {Patent Literature 1} Japanese Laid-open Patent Application No. 2003-322002    {Patent Literature 2} Japanese Laid-open Patent Application No. 2008-151112